Space telegraphy.



No. 840,909. 'PATENTED JAN. 8, 1907. V

S. UABOT.

SPACE TBLEGRAPHY.

APPLICATION FILED NQV.25,1905- 2 SHEETS-SHEET 1.

IHVEHTEI K @zww MQUM M No. 840,909. PATENTED JAN. 8, 1907.

S. OABOT. SPACE TBLEGRAPHY.

APPLICATION FILED NOV.25. 1905.

2 SHEETS-SHEET 2,

UNITED ATE? WPATEN T OFFICE.

TELEGRAPH AND TELEPHONE COMPANY,

OF BOSTON, MASSACHU- SETTS, A CORPORATION OF MAINE.

I SPACE TELEGRAPHY.

Specification of Letters Patent.

Patented Jan. 8, 1907.

Original application filed November 18, 1905, Serial No. 288.032. Divided and this application filed November 25, 1905. Serial No. 238,989.

To (all whmn it Duty concern.-

Be it known that I, SEWALL GABoT, a citizen of the United States, and a resident of Brookline, in the county of Norfolk and State of Massachusetts. have invented a new and useful Improvement in Space Telegraphy, of which the following is a specification.

Mv invention relates to the art of trans- 'IO mitting intelligence from one station to another by means of electromagnetic waves Without the use of wires to guide the waves to their destination; and. it relates more particularly to a complete system-for transmit- 1 5 ting and receiving such waves The object of the present invention is to provide a system whereby the well-known operation of breaking such as used to-day in wire-telegraph traffic as worked out in dupleX and quadruplex systems, may be applied to the handling of wireless-telegraph traffic.

With this object in view my invention comprises' a receiving system connected to an elevated transmitting-conductor system at a point which, during the operation of the transmitting system. has practically zero potential to ground; and it further comprisr s a key provided with means, whereby, at the commencement of the downward movement of said key, the receiver is rendered inoprrative, the receiving system is automatically short-circuited, and the transmitting system is connected to earth, thereby automatically 3 5 putting said transmitting system incondition for transmitting; whereby, at the completion of the downward movement of said key, the said transmitting system is energized; whereby, at the commencement of 0 the upward movement of said key, the transmitting system is deemrgized; and finally, whereby, subsequently to such denergization the receiving system is put in condition for receiving by disconnecting the transmitting system from earth, automatically opening the short circuit around the receiving system, and rendering the receiver operative.

For the purpose of more fully disclosing my invention, 1 have illustrated and shall particularly describe one specific embodithat I do not limit myself thereto, for my invention is capable of many other embodiments.

My invention may best be understood by having reference to the drawings which accompany and form a part of this specification, and in which the same reference characters are used to designate several figures.

1n the drawings, Figure 1 is a diagram representing an organization of apparatus and circuits whereby the objects of my invention may be carried into effect. Fig. 2 is a plan view of one form of key and associated apparatus which in practice I have found well suited for performing in the desired order the series of functions hereinbefore set forth. Fig. 3 is a side elevation of the key shown in Fig. 2; and Fig. 4 is asection taken on the line 4 4 of Fig. 2, looking in the direction of the arrow, and showing in end view an elevation of the cooperating parts of the receiver.

In the figures (1 (7, C, arccondensers.

L is an induct ance-coil.

M is a transformer whose primary and secondary windings I, and I are preferably so spatially related as to produce a transformer of large magnetic leakage. The separation of said windings is herein shown for the sake of clearness as a transverse separation, although in practice the separation is aXial.

,M is a transformer adapted to raise the potential impressed upon its rimary windlng I, to a very high potentia in its secondary winding 1' M is a transformer whose primary and secondary windings I and I are preferably so spatially related as to produce a transformer of large magnetic leakage. Here again the separation of the coils is for the purpose of clearness shown as a transverse separation, although in practice the separation is axial.

S is a spark-gap.

E is an earth connection.

P is an oscillation-responder of any suitable type which comprises separable cooperating parts and is herein illustrated as an electrolytic cell, the anode of which is a Wollaston electrode.

T is a telephone or other suitable signalment thereof, although it is to be understood 1 indicating device.

like parts in the transmitting system to ground, and then' with the battery B and adjustable contact ter.

Inwireless or space telegraphy, as in telegraphyby connecting wires, it is often desirable for the receiving operator to interrupt the transmitting operator, that is to say, if

the receiving operator should fail to get a portion of a message, it is desirable that he should be able 'to' immediately notify the transmitting operator of the fact so that the latter may repeat that portion of the message which the'former failed to get, instead of having to wait until the transmitting operator has finished sending the message and then notifying him that a ortion of the message had not been received In wire telegraphy, especially as developed in the practical op eration of the duplex and quadruplex systems, this is accomplished very simply in a manner well known to those skilled in the art of telegraphy, but in wireless telegraphy the peculiar difliculties involved in arranging the circuit connections in transmitting and receiving systems, as well as the differences between said circuit connections, and also the extreme sensitiveness of the oscillation-responder render the operation of breaking more diflicult and, so far as I am advised, no system has yet been devised whereby such operation may be effected.

In all the embodiments of the present invention, I accomplish the hereinbefore-stated objects by means of a sending-key or other" sending device provided with auxiliary mech- 'anism whereby the key or sending device performs a series of functions in a definite order. These are, first, rendering, the re sponder inoperative at the beginning of the downstroke of the key and connecting the closing the power-circuit.

In that embodiment of the present invention shown in Fig. 1 the receiver or responder is rendered inoperative by physically separating'the cooperating parts thereof. By the term rendering the receiver inoperative as used in the specification and claims I=desire to be understood as meaning an operation whereby the receiver is rendered incapable of performing its natural functions, and although I have described in this specification only one way of effecting this result by sepa rating the electrodes of the receiver, it will be obvious to those skilled in the art that man other simple ex'pedients may be devise for this purpose so that it is not my intention to limit myself to the particular means disclosed for rendering the receiver inoperative as aforesaid, inasmuch as I consider any suitable means, whereby the cooperating parts of the receiver may be sepa rated, within the scope of my invention. It is to be understood also that although I have herein shown for the purpose of more clearly the key sistent train of waves illustrating my invention one particular form of oscillation responder or receiver, namely,

. an electrolytic receiver, nevertheless my invention is not limited in its use to a system provided with such a receiver but may be used in connection with any suitable receiver. the parts of which are capable of physical separation.

Referring now particularly to Fig. 1., upon the depression of the key Kfor the purpose of sending the signal, the first operations effected are the separation of the terminal W of the receiver P from its cooperating member, thereby rendering said receiver inoperative or incapable of responding, and the closure of the contact'lc thereby grounding the transmitting system and simultaneously short-c-ircuiting the receiving system. The said terminal W is adjustably attached to the key so that the first slight movement of the latter will raise the'terminal W out of the electrolyte contained in the cell P. The transmitting system now being earthed and the cooperating parts of thereceive'r being separated, the system is in condition for transmittingand the further depression of K effects such transmission by the closure of the circuit containing the source of energy A, the primaryof the high-potential transformer M and the contact it. By such closure of the contact 7c the alternating current developed in the primary I, is transformed into a high-potential current in the secondary I and such current charges the condenser C to a corresponding high potential. The discharge of said condenser across the gap S develops high potential, high-frequency electrical oscillations in the sonorous circuit C S 1,. These oscillations are simple harmonic in form, if as set forth in United States Letters Patent Nos. 714,832 and 767,984, the windings of the transformer M are so spatially related as to render the sonorous circuit the equivalent of a circuit having a single degree of freedom. While such relation between the windings of said transformer is preferred, it will be understood that my invention is not limited thereto but is capable of ap lication to anysystem irrespective of the orm of the oscillations developed therein or the waves transmitted therefrom.

At the point 0, the receiving system is, connected to the transmitting system. This receiving system for the purpose of more clearly illustrating my invention is shown as embodying the system of circuits described in United States Letters Patent N 0. 767,994 and reference may be had thereto for a more complete description than-need be set forth herein of the manner in which the reactance of the elevated conductor per se, thecoil I and the coil L is balanced by the reactance of the parallel branch circuit C I for a perof the frequency to which the resonant receiving-circuit C I after such opening,

station is signal nected to earth by a conductor of practically .Zero .impedance so that evenwhen oscillations of large current value are being developed in the elevated transmitting-conductor system E 0 0 25 I V there exists between the points 0 and 0 which form the terminals of the 'receivingsystem no dilference of potential, or at least not a sufficient difference of potential to damage delicate parts of the receiving system. So far as I am aware no combined transmitting and receiving system has heretofore been devised in which the receiving system is connected at a point of zero potential with the transmitting system.

When the operator has depressed the sending-key to its full extent for a sufficient length of time to produce the desired signal element, the key is allowed to regain its normal position and the following cycle of operations is effected: First the contact 7c is opened thereby denergizing the transformer M; andsecond the contact 76 is opened an appreciable intervalof time after the opening of thecontact kthereby ungrounding the transmitting system and automatically opening at the point k the short circuit around the terminals 0, 0 ofthe receiving system an appreciable interval of time after the opening of the aforesaid contact 7c. The object of providing for the time interval between the opening of lcand k is-to permit the completeqsubsidence of electrical movement in.

the transmitting system before breaking its connection to earth. Simultaneously with the opening of the contact k, or before or the immersion of the anode W in the electrolyte contained in the cup or cell P .is effe'cted,- thereby'rendering the receiver operative.

An appreciable interval of time must ela se between the sending of signal elements an it is during such intervals of tifne when the key is in its normal. osition that the sending operator, who sen s with the head-telephone T placed over his ears, may ascertain that the receiving operator at the distant ing break. Said receiving 0 erator havingfailed to receive a portion of t e message transmitted to his station, depresses his sending-keyimmediately upon such-failure to receive a word or portion of a message and sends a redetermined signal indicating that he Wishes the transmission stopped. The waves sent out by said receiving operator develop in the vertical at the station from which the message is being sent to said receiving operator electrical 0s, cillations which pass to earth E by way of the secondary 1 which for said oscillations operates merely as an inductance, the coil L and the parallel branch circuit, when the key upon ceases his K is in its normal position and the contact accordingly is open. Said oscillations are of such frequency that for them the elevated conductor system V E has zero reactance, so that currents of relatively large amplitude are. developed in the resonant receiving-circuit and create at the terminals of the condenser C asufficient difference of potential to cause the oscillation-responsive device P to respond and produce a signal in the telephone. This signal is an indication to the transmitting operator that the receiving operator is signaling break, and he theretransmission and receives from the receiiing operator instructions concerning the repetition desired by-the latter. If the oscillations created in the elevated conductor by the waves sent out fromthe distant receiving-station, whose operator desires to .break, are so created when the key K is down, it is obvious that such oscillations will not effect the operation of the receiver P, but it will be observed that as soon as the key is again in its normal position the oscillations will affectthe receiver and the transmitting operator will then cease to send.

The device W in Figs. 1, 2 and 4 is known in the art as the Wollaston anode and consists of a Wire, very large'as compared with the silver-coated platinum Wollaston wire, inolosed in a capillary tube and having its end surface only exposed toan electrolyte contained in the cup of the receiver P. The construction-of this ,Wollaston anode need not further be specified herein, inasmuch as full directions for making the same will be found ina paperby Dr. William H. ,Wollaston in the Philosophical. Transactions 0 the Royal SocietyofLondrm, Vol. 91, Part I pp. 430 to 432, published 1801.

. It will be noted that the signal-indicating device T and part of the potentiometer resistance R are included in the circuit of the oscillation-responder P, but such-devices do not 0 erate as choking-coils, inasmuch as they ave such large distributed capacity as to' offer but small impedance to oscillations of the frequencies employed in space telegraphy.

I shall now describe one s ecific embodiment of the key K and auxi iary or associated devices whereby the aforesaid cycle of operations may be effected. 1 Referring to Fig. 2, 1' is a base carrying the base-plate 2 of the key which is pivoted to the standards 2 by the screws 3 3 in the usual manner. The key-arm 4 is provided at one end with a fin ger-piece 5 and at the other end with a contact '8 made preferably 1 of silver or other metal Whose vapor is non-conducting. For the purpose of simplifying Fig. ;:2, the upper contact with whichthelower contact 8 ooo erates has been omitted from'Fig. 2 and is s own in Fig. 3 supported from a cross-piece 11 which is mounted upon a standard 10 se-,

cured to the base by screw 12. Supported by and pivoted to the standards 13 13 is a rod 14 preferably of insulating material, carrying a projection 15 which is provided with an adjusting-screw 16, the end of which rests upon the key-arm 4. About midway between the standards 13 13, a screw 17 carrying an adjustable weight 18 is passed through the rod 14, whereby the screw 16 is held in contact with the rod 4 and the anode W is, in. the normal position of the key, maintained immersed in the electrolyte of the cell P. It will now be obvious that upon a very slight depression of the key is, the rod 14 will be rotated about its pivots and the member W which, in that particular embodiment of my invention illustrated in'Fig. 2, is adjustably attached to the projection 38 secured to and the anode W the rod 14, is moved out of operative relation with its coo crating member P. As shown in Figs. 2 an 4 the'cell P is conductively connected to the metal plate 18 and said plate are conductively connected to the potentiometer resistance R.

The means whereby the grounding of the transmitting system is effected, is herein illustrated as the'contact-screw 0 which cooperates with the spring'o and thereby connects the transmitting system to earth at E and at the same time connects the receiving system to the transmitting system at. the point 0 which has zero potential to ground. This operation is indicated in-diagrammatic 'form in Fig. l likewise by the contact 16" between the screw 0 and spring 0.

The last of the aforesaid cycle of operations 18 efiected when the key has been fullv' depressed and the silver block 8 brought intl) contact wltn"the silver block 9, an indicated in diagrammatic form in Fig. 1 by the contact It. It will now be obvious that as the key is brought to its normal position by the spring 6 adjusted by the screwfi, such normal position being determined by the screw 7, the contact S leaves its cooperating member 9, thereby opening the power-ciroperation cult; and then the screw 0 leaves the spring 0 thereby. ungrcundlng the transmitting system and opening at the point 16 the shhrt. circuit around the terminals 0, 0 of the recelv'ing system, and simultaneously or afterward the member W is brought into operative relation with its cooperating member P.

Thisapplication is a division of my ap' lication Serial No. 288,032, filed N ovem er 18,1905.

Although for the purpose of more clearly disclosing my invention I have described with great particularity a specific system of circuits and a specific mechanical device, it

system by the movement. 0

is tobe understood that I do not limit myself to said system or device, inasmuch as many modifications may be made in each without departing from the spirit offmy invention.

1 claim- 1. In a space-telegraph system, a'transmitting system, a receiving system includin a receiver, a sending-key and means operate by said key for automatically rendering said receiver inoperative by separating the coopcrating parts thereof.

2. In a space-telegraph system; a transmitting system, a receiving system includin a rece1ver, and means associated with said transmitting and receiving systems for rendering said receiver inoperative by separatingdthe cooperating parts thereof, grounding sai trical oscillations in said transmitting system. 3. In a spacertelegraph system, a transmitting system, a receiving system including a receivena sendingkey and means for eifecting the separation of the cooperating parts of said receiver by the movement of said key.

4. In a space-telegraph system, a transmitting system, a receiving system, an elevated conductor normally grounded through said receiving system, a=sending device, and means. directly connected with said sending device for short-circuitin said receiving said sending de vice.

5. In a space-telegraph system, a transmitting system lncluding a sending device,- an elevated conductor conductively connected to a contact member carried by said sending device, and a receiving system the terminals of which are conductively connected to said contact member and to a grounded member cooperating with said contact member, respectively, whereby the movement of said sending device will short-circuit said receiving system. 1

6. In a space-telegraph system, a transmitting system, a. receiving system, an elevated conductor normally grounded through said receiving system, a sending device, and means conductively connected with said sending device for directly grounding said elevated conductor and short-circuiting said receiving system by the movement of said sending device.

In testimony whereof Ihave hereunto snbscribed my name this 22d day of November, 1905-. SEWALL CABS-'1.

Witnesses:

FRANK G- BLAISDELL, Gno. K. Woonwonrn.

transmitting system and creating elec- 

